Automatic railway-signal system.



' No. 657,!70. Patented Sept. 4, I900.

J. W. LATTIG.

AUTOMATIC RAILWAY SIGNAL SYSTEM.

(Application filed June 6, 1900.)

(No Model.)

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TUNTTED STATES PATENT OFFICE.

JACOB W. LATTIG, OF WEST BETHLEHEM, PENNSYLVANIA.

AUTOMATIC RAILWAY-SIGNAL SYSTEM.

'S';PECIFICA'IION formingpart of Letters Patent No. 657,170, dated September 4, 1900.

Application filed June 6, 1900- T0 aZZ whom, it may concern:

Be it known that I, JACOB W. LATTIG, a citizen of the United States, and a resident of West Bethlehem, county of Lehigh, and State of Pennsylvania, have invented a new and useful Improvement in Automatic Railway-Signal Systems, of which the following is a specification.

Under my invention the signal is operated by fluid-pressure applied by a pump, both the pump for applying and the device for relieving the pressure being operated by electrically-controlled instrumentalities automatically governing their operation by means of the usual track-circuit and track-relay included therein. Each signal is provided with its own pump-motor and pressure-controlling device, so that fluid-pressure for operating each signal can be generated, applied, and controlled without respect to or dependence upon the operating devices or means of any other signals.

- The nature of my invention can best be explained and understood by reference to the accompanying drawing, in which I have represented to a large extent diagrammatically one insulated track-section provided with a semaphoresignal and means for automaticallyoperatingthesame. Theremaybeasmany insulated track-sections or blocks of course as desired, but each of them will be provided with an independent system of signal appliances. V

A is an insulated railway-track section or block of indefinite length. The rails of the section form part of an electric circuit 1, usually termed the track-circuit, which includes the coils of a relay a, usually termed the track-relay, whose armature b is employed to control contacts 0, through which other electric circuits are completed. When the track-section A is clear, the relay is energized. When, however, a car is on the track-section, the track-circuit Will be completed through the wheels and axle of the car and the relay will be short-circuited. Thus far there is nothing new in the system.

B is the semaphore-signal pertaining to track-section A, having its hinged blade or arm jointed to an operating-rod D, Which is connected or attached to a piston E in the fluid-pressure cylinder F. The fluid when Serial No. 19,307. (No model.)

admitted under lowthe piston consequently the operating rod D, with the effect of bringing the signalto safety position. Any suitable fluid can be used. I prefer to employ oil, which is drawn from areservoir or tank G by a pump H and by the latter is forced into the fluid-pressure cylinder. The fluid is drawn from the reservoir by the pump through a pipe d, havingapuppet or other valve 6 to prevent backflow from the pump to the reservoir, and it passes from the pump to the pressure-cylinder F through a pipe f, provided with a puppet or other valve g to prevent backflow of the liquid through this pipe from the pressure-cylinder to the pump.

The pipe through which the liquid is drawn off from the pressure-cylinder F and returned to the reservoir is shown at h. It is controlled by a valve t, which when open permits the liquid to pass from the pressure-cylinder F directly into the reservoir, thus allowing the piston E to descend, with the effect of bringing the signal to danger position.

It remains now to describe the means for operating the pump H and controlling valve t'.

The pump is operated by an electric motor M, to the shaft of which is attached acranltpin m, that works in the slot j of the pistonrod of the pump. The electric motor is in cludedin a circuit 2, which I term the motorcircuit, from a generator or other source of electric current, (typified at N,) said circuit being completed through two sets of contacts cl, the former controlled,as already stated, by the track-relay and the latter controlled by the fluid-pressure piston E or some part moving in unison therewith, the means employed for this purpose consisting in the presentinstance of a loose pin it, which when the piston E about completes its upward movement is raised by said piston, with the effect of lifting the spring contact-strip o,and thus separating the contacts at Z. The valvet' is controlled by means of a rod p, connected to it and passing up through the top of the reservoir G to an armature-lever r, to which it is attached. This armature-lever is controlled by a magnet R in a branch circuit 3 from circuit 2, said branch circuit (the pressure-controlling pressure to the cylinder be- E will raise the latter, and,

circuit) also including and ,being completed through the contact 0. Then the armaturelever 'r is attracted by its magnetR, the valve t' will be drawn down and held closed. When, on the contrary, the magnet is denergized, the valve will be free to open.

In the position in which the parts are shown in the drawing the signal is at danger and the motor-circuit 2 and pressure-controlling circuit 3 are closed. This is the position which the parts will assume just after a train has left the block or track-section A. The operation then proceeds as follows: The motor M will start and will operate the pump, which consequently will draw liquid from the reservoir and force it into the pressure-cylinder E. This liquid, being prevented from returning through the pipe h by the valve 2', (which is held in closed position by the armature-lever '13) will gradually raise the piston E, and thus lower the signal from danger to safety position, until as the piston reaches its uppermost position it will by means of the pin 'n and contact-strip 0 separate the contacts atl, thus breaking the motor-circuit 2 at that point. The parts referred to are shown in this position in dotted lines. The motor now ceases to act, and consequently the pump stops work; but the track-circuit through the track-relay being still active the contacts at c are held closed, and consequently the pressure-controlling circuit 3 remains intact, with the effect of causing the valve *6 to be held tight shut by the action of the magnet R and armature-lever r. There is no escape therefore for the liquid that has been pumped into the pressure-cylinder F,

, and thus the signal is maintained in safety position. Such will be the condition of affairs until by an entering train or some other means the track-relay a is short-circuited. As soon as this takes place the contacts at 0 will be separated, with the effect of breaking both of the circuits 2 3 at this point. Consequently the valve '5 will be free to lift and the oil from the pressure-cylinder F will [low back through the pipe it into the reservoir, thus allowing the piston E to descend and causing the signal to go to danger. On descent of the piston the contacts atl will be reestablished; but inasmuch as the contact at 0 will still be open the motor-circuit will remain broken and the motor will be'out of action. As soon as the block or track-section A is again clear the relay a will be energized, the contacts at 0 will be again made, the circuits 2 3 will be reestablished, and the sequence of operations above mentioned will be repeated.

Manifestly the details of the circuit arrangements can be widely varied without departure from my invention. The two circuits 2 3 might, for example, be arranged in full multiple to each other-that is to say, each circuit may have its own separate wiring instead of a portion of the wiring being common to both circuits, as shown in the drawing-and the control exercised by the track-relay over the contacts which it is designed to govern may be either direct or indirect-as, for instance, the motor -circuit may be entirely distinct from the circuit whose contact a is directly controlled by the relay, and the latter circuit may include an instrument which in turn controls contacts in the motor-circuit. Modifications of this character, however, are well understood by those skilled in the art and require no de tailed explanation. I remark also that when instead of oil a fluid, such as air, is employed the reservoir G may be dispensed with. Further, the means or device for controlling the set of contacts at Z in the motor-circuit may be actuated either mediately or immediately by or from the signal-actuating mechanismthat is to say, it may be actuated either directly by some moving part of said mechanism or indirectly from said mechanism through any suitable intermediary.

Having described my invention, what I claim herein as new, and desire to secure by Letters Patent, is as follows:

1. In an automatic railway-signal system, the combination with an insulated track-section or block, a track-circuit and a relay included therein, of a signal, actuating mechanism for said signal including a fluid-pressure cylinder and piston, a pump for supplying said cylinder with fluid, an electric motor to actuate said pump, an electric circuit including said motor and two sets of contacts in said motor-circuit controlled the one by the track-relay and the other by means actuated by or from the signal-actuating mechanism, substantially as set forth.

2. In an automatic railway'signal system, the combination substantially as hereinbefore set forth of the following elements: an insulated track-section or block, a track-circuit and a track-relay included therein; a signal, and signal-actuating mechanism including a fluid-pressure cylinder and piston; a pump for supplying fluid to said cylinder; an electric motor to actuate said pump; a motor-circuit and two sets of contacts therein controlled the one by the track-relay and the other by means actuated by or from the signal-actuating mechanism; a valve controlling the outlet from the fluid-pressure cylinder; a magnet, armature and connections for controlling said valve; a pressure-controlling circuit including said magnet; and contacts in said last-named circuit controlled by the track-relay.

In testimony whereof I have hereunto set my hand this 4th day of June, 1900.

' JACOB W. LATTIG.

Witnesses:

ROBERT S. SIEGEL, RoB'r. H. WOLLE. 

